Nearly a third of patients showed abnormalities in multiple organs, particularly in the lungs, brain and kidneys, five months after COVID-19 infection, revealed a study looking at the longer-term impact of the infectious disease.

The study, published in The Lancet Respiratory Medicine, based on magnetic resonance imaging (MRI) scans showed that lung abnormalities were significantly the highest almost 14-fold among patients discharged from the hospital for COVID than in the control group.

The abnormal findings involving the brain and kidneys were three and twice higher, respectively.

The extent of abnormalities on MRI was often influenced by the severity of the COVID-19 infection the patients had experienced and their age, as well as comorbidities.

"We found that nearly one in three patients had an excess burden of multiorgan abnormalities on MRI relative to controls," said Dr Betty Raman, University of Oxford’s Radcliffe Department of Medicine.

The findings come from a multi-centre MRI follow-up study of 500 post-hospitalised COVID patients. The paper presents the results of an interim analysis of 259 post-hospitalised COVID-19 patients and 52 controls.

The participants, who were recruited across 13 sites in the UK, underwent MRI scans covering the heart, brain, lungs, liver and kidneys an average of five months after discharge from hospital. They also had blood tests and completed questionnaires.

The study found that while some organ-specific symptoms correlated with the imaging evidence of organ injury -- for example, chest tightness and cough with lung MRI abnormalities -- not all symptoms could be directly linked to MRI-detected anomalies.

The heart and liver damage levels in the former hospitalised COVID patients were similar to those in the control group.

The paper also confirmed that multi-organ MRI abnormalities were more common among post-hospitalised patients who reported severely impaired physical and mental health after COVID-19.

In addition, Raman said that people with multiorgan pathology on MRI that is, they had more than two organs affected -- were four times also more likely to report severe and very severe mental and physical impairment. 

"Our findings also highlight the need for longer-term multidisciplinary follow-up services focused on pulmonary and extrapulmonary health (kidneys, brain and mental health), particularly for those hospitalised for COVID-19," she noted.